Nios® V Processor: Lockstep Implementation

ID 833274
Date 10/07/2024
Public
Document Table of Contents

6.2.3.6. ALARMS Interfaces

Use the following fRSmartComp ALARMS interfaces to control fail-safe and other alarms’ detection actions as you need according to the Safety Architecture:

  • OKNOK[1:0]: Usually to put the system in safe-state, by hardware (Altera recommends from a Functional Safety point of view) or by software (running on the Supervisor, not on the Nios® V processor).
  • ERROR[1:0], WARNING[1:0] and INFO[1:0]: Connect according to your Safety architecture, also to put the system in safe-state.
For example, according to the system-level safety architecture as follows:
  • ERROR is left unconnected (as OKNOK is already used),
  • WARNING is used to activate a yellow LED on the system dashboard, and
  • INFO is used to trigger a Nios V interrupt request (An alternative to INTREQ).
The following figure contains an example of connection made with based on the listed implementation below:
  • Connects the reserved interfaces as requested above.
  • Not using Silent Mode Interface.
  • Not using Interrupt Request.
  • Not using Alarms Interface
Figure 24. Connecting System Interface